Such fuselages are made up of a number of components. An aircraft or spacecraft, such as for example an aeroplane, is not only exposed to great load changes and stresses but also considerable temperature differences during operation. For example, at a specific cruising altitude, the outside temperature on the outer side of the fuselage is approximately −55° C., while the inside temperature in the area of the pressurized cabins is kept at a value of approximately +20° C. This is performed by means of an air-conditioning system. In the case of conventional aircraft fuselages, the inner side of the fuselage is provided with a thermal insulation, which also forms an acoustic insulation.
A fuselage may be of a single- or multi-shell form, in particular a double-shell form.
FIG. 7 illustrates a partial sectional view of a single-shell fuselage 1 based on a technique known to the applicant with a shell element 2, which has stiffenings 15, for example so-called stringers, on its inner side. The conventional construction of an insulation 18 comprises insulating layers, which usually consist of glass wool and are integrated in an enclosure 17, for example a film of plastic, between the inner side of the shell element 2 and an inner structural element 7, for example a lining of the cabin. The lining is produced for example from a GRP material. It may also have side panels 16. This arrangement performs the functions of thermal insulation and sound insulation of an interior space 20 with respect to an outer side 19 outside the fuselage 1.
However, the additional weight of the insulation, its space requirement and the consequently necessary installation requirement are considered to be disadvantageous here. Furthermore, with this arrangement, an accumulation of condensation can lead to increased weight and a risk of corrosion, which means that a corresponding amount of maintenance work is required. The elimination of accumulations of moisture by drying or exchanging the insulation 18 along with the enclosure 17 is disadvantageously necessary.
Therefore, concepts for a fuselage of a double-shell type of construction have been proposed, as described in DE 101 54 063. FIG. 8 shows in this respect a partial sectional view of a portion of a prior-art double-shell fuselage 1, which is produced for example from fibre reinforced materials.
The shell element 2 of the fuselage 1 has an outer shell element 3 and an inner shell element 4, which are arranged at a distance from each other and form a core interspace 5. The core interspace 5 is provided with a core structure 6, which comprises for example a folded honeycomb structure of GRP, carbon fibre reinforced plastics or the like, forms a shear-resistant laminate that is effective in terms of structure mechanics (sandwich structure) and stabilizes the fuselage structure. At the same time, the core structure 6 has a thermal and acoustic insulation and, by its compactness, increases the interior space of the cabin.
Air can be admitted to the core interspace 5 by means of an air stream 10, which is indicated by arrows, whereby so-called moisture management is possible with respect to condensation in the core interspace 5. The inner shell element 4 faces with its inner side towards the interior space 20, where the lining, for example a decorative film, is arranged on it.
A disadvantage here is that further additional insulating work is required, since otherwise the aim of an inner wall temperature that can be fixed, for example at +20° C., cannot be achieved.
FIG. 9 illustrates a customary system of pipes 12a of an air-conditioning system (not shown) of an aeroplane. A portion of a fuselage 1a with a lateral portion of the system of pipes 12a is presented in a simplified form, given by way of example. A system of coordinates indicates a longitudinal direction x, a transverse direction y and a vertical direction z of the aeroplane for orientation. In the x direction, there extends a lower X line 13a and an upper X line 14a, which are connected by means of Z lines 15a running substantially in the z direction. Indicated in the middle are two further intermediate lines 16a, running in the x direction. The air-conditioning system (not shown) is connected to this system of pipes 12a and controls the ventilation and temperature of the cabin, also maintaining the internal cabin pressure. Furthermore, the air-conditioning system is also used for ventilating and cooling areas outside the cabin, such as for example a cargo hold, avionics rack, etc. The air-conditioning system feeds the system of pipes 12a, which is designed as a compressed-air system and is routed throughout the entire aeroplane. Warm air is passed from the bottom upwards from the lower X lines 13a via the Z lines 15a into the upper X lines 14a and intermediate lines 16a and into the cabin. The Z lines 15a run behind a cabin lining.
Such supply lines may have the following disadvantages. Depending on the cross section, a relatively great installation space is required. The lines are of a certain weight, which adds to the weight of the aeroplane. Such a system of pipes requires a certain amount of installation work. Furthermore, the lines can be easily damaged, since they have only small wall thicknesses.